Air-compressor.



No.s6o,82e. PATENgSsD-'JULY 23,1907.

W.RBAVBLL. l

AIR COMPRESSOR.

APPLIOATION FILED HEPT.15.1904.

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No. 860,826. PATENTBD JULY 23. 1'907. W. REAVBLL.

AIR COMPRESSOR.

APPLIOATION FILED sEPT.15.19o4.

5 SHEETS-SHEET 2.

No. 860,826. PATENTBD JULY 23, 1907. W. REAVELL.

. AIR COMPRESSOR.

APPLIGATION FILED sBPT.15.19o4.

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No. 860,826. PATENTED JULY 23, 1907. v

W. REAVELL.

AIR COMPRESSOR.

APPLICATION FILED s511115. 1904.

5 SHEETS-SHEET 4.

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No. 860,826. j PATENTBD JULY 23, 1907.

W. REAVBLL. I

AIR COMPRESSOR.

APPLIUATION FILED sBPT.15.19o4.

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muren STATES f WILLIAM RAVELL, OF IPSWICH, ENGLAND.Y

.AIR-COMPRESSOR.

I To all whom it may concem: f5 Be it known that I, WILLIAM REAVELL, a subject of the King of the British Dominions, residing at Ipswich, and whose post-ofhce address is Ranelagh Works, Ipswich, in the county of Suffolk, England, have invented certain new and useful Improvements in Air- Compressors', of which the following is a specification.

Thisinvention relates to air compressors, and constitutes improvements on the invention described in the specification toUnited States Letters Patent dated June 11th, 1901, No. 676,080, granted to me.

In the further description of this invention, refer ence is made to the accompanying drawings in which Figure 1 is a sectional elevation of my improved four cylinder air compressor the sections of cylinders a and b being taken on different planes; Fig. 2 is an outer elevation of the same; Fig. 3 is an elevation of the said compressor at right angles to Figs. l andV 2, and of an electric motor combined therewith to drive it, part of the frame being broken away to show the crank shaft and one of its two bearings, the other one being shown in outer elevation at the left hand end of the motor.' Fig. 4 is aplan taken from above the high pressure cylinder d. Fig. 5 is an elevation of the inlet and outlet valves of cylinder'd; Fig. 6 is a section through Fig. 5; and Figs. 7, 8, 9 and 10 are details of stuffing box packing rings, and Fig. ll is a section oi the cylinders and annular frame (similar to Fig. l) showing the connection between the cylinders.

ln this-present invention four main cylindeis, a, b, c and d are radially arranged in a ring shaped frame e, which is combined with an'electric motor, turbine, or other suitable motive power f, the motor driving shaft f 1 extending into the compressor to drive the same by a crank-pin, f2. The crank-pin in its revolutions transmits motion through intermediate devices 'to pistons within the several cylinders, which are adapted in succession to compress air, subsequently conveyed away through water cooled pipes g and gf; the water being contained within the ring shaped frame, e. The air is preferably compressed in three stages'in passing through the four main cylinders, two of them (a, b), acting as low pressure cylinders, from which the air, cooled as aforesaid, is passed to the remaining two cylinders (c, d),V in succession to complete the process; -a high degree of compression being thus made possible. In some cases I may modify this by compressing the air in four stages, the .cylinders a, b being of suitable dimensions; or I may employthe cylinders as a two-stage compressor, without departing from the nature of the invention.

In connecting the improved air compressor to a high Specification of Letters Patent.

Application filed September 15, 1904. Serial No. 224,602.

Patented July `23, 1907.

speed engine, -electric motor, or other source of motive power, it is found important to use but one driving shaft having a crank pin at one or both ends, so that the electric motor f (for example), is connected directly to the air compressor to practically form one combined machine; the armature shaft f l being prolonged into the compressor and adapted to drive the pistons at its own number of revolutions, or conversely, ,the crank shaft of the compressor being prolonged through the field magnets' to receive the armature; or' similarly arranged for any other motive power employed.

The center lines of the cylinders are all arranged upon the same plane converging at the point of intersection with the axial line of the shaft f1, the said plane being that which is described by the center of the length of the crank pin f2 in its revolutions; the outer centers of -the cylinders being equally spaced apart, (or approximately' so), around the ring shaped frame e. Consequently the cylinders are arranged in two pairs, as it were, a center line passing straight through two 0ppositely placed cylinders, and at right angles to a similar center line passing through the other pair of oppos'itely placed cylinders. In one pair, a and b, the 0pposite pistons are adapted to be acted upon by the revolutions of the crank pin f 2 through the intervention of two connecting rods al and b1; while the pistons ofthe other pair are formed like plungers cl and d1, connected together by a yoke h forming a slotted -crosshead, in which a slipper hl (which may be divided) is adapted to slide to and fro, as the crank pin f 2 revolves tion, while keeping a continuous thrust upon thel crankpin brass or bushing f 4, and for a retaining ring f5; the other ends o i the two connecting rods al and b1 are cylindrically. formed at right angles with the line of `the rod in each case to enable it to be seated in a suit.

able bearing in its piston a2 or b2, and provision is made for removingv each rodl sidewise from its corresponding piston.

Thetwo largest borecylinders a and b are placed oppositely as shown in Fig. 1, each of their pistons being acted upon by the crank pin f 2 through the connecting rods al and b as aforesaid, and the rst stage of compressing air takes place within these cylinders in the well known manner. The air, as compressed,

-passes from the delivery belts r and s of these cylinders through non-return valves, into the pipesg leading from the two cylinders a and b to the valve box or inlet t of the next largest cylinder c, where it is subjected to the second compression. From thence-it passes through the delivery valve box or chamber u into two pipes g1 situated behind those marked g and'leadingito the Vfourth cylinder, d, where it receives the third stage of compressing, and from thencef,throughI a delivery valve, the highly compressed air passes through the coolingcoil above cylinder d, and is conveyed by a suitable pipe or pipes wherever required.

Fig. 1 shows the inlet valve of the cylinder a. An`

ordinary outlet valve` is situated between the cylinder a and the delivery belt r, but not shown. The cylin der b is arranged like cylinder a. The valves of the fand therefore expanding the enteringair, thus obtain- -ing the utmost eiciency in supplying air of suiiicient 'density for the compressing pistons to act upon. A

pump or other suitable means should be provided for supplying and circulating the cooling Awater.

Special packing rings k of metal are used in some cases, instead of leather, the latter being unsatisfactory in stuiiing boxes when opposed to a high degree of com-- pression, but sometimes metal rings are combined with leather as shown in the stuffing box of c. The piston rings l are oi metal,A shown in section in cylinder a, Fig. l, and comprise two narrow outer rings cut into segments, being backed'up by a wide spring follower inner` ring, the narrow rings being turned to fit the bore of the cylinder so that the distortion oi the rings and unequal wear of the cylinder is avoided; and in some cases I admit air under pressure behind both'kinds of packing rings.

The largest or first stage compression cylinders, a, b, are each combined with a small outside cylinder called a pilot cylinder, a3, and b3, respectively, into which the main piston extends like a plunger, these plunger pistons o4 and b4 are also provided with similar` packing rings l, to 'those alreadydescribed. A space m at the back oi each pilot piston is connected to the first stagehair delivery or receiver space, thus constantly exerting a thrust upon its corresponding piston o.1 or b4 and connecting rod, al and bl, always keeping the inner end of the rod pressed upon its crank pin bearing or bush f4 so that no lost motion takes p1ace. Constant pressure and silent working are also insured on the second and third'stage plunger pistons a? and b", because they are subjected to the air pressure in the receiver or pipe from which they obtain their supply of air, and on the crank pin through the yoke h and slipper h cross-head connection between the second and third stage pistons, c1 and d1; so that eiciency is secured in compressing by the cooling `oi cylinders 'and pipes, and silent working thus obtained even when working at five hundred revolutions per minute.

Suitable suction and delivery valves, are provided at the required points for their duty; lubrication takes place by splashing trom the central chamber formed sodass by inclosing that part oi .the vframe by the outer-cover o 'Large openings, .p and p2 are formed in the frame and 'faced to facilitate construction, those in theinner wall ofthe frame are indicated by p,` and are all one size to provide for the interchange oi cylinders7 the latter being adapted by flanges, p1 more or less extended, to beseated therein; the` other holes, p2, in the outer wall of the frame, being also oi one size, (but larger than p), adapted to receive on the face of the llanges a bonnet or cover q screwed 'in-position over each cylinder, as shown in Fig. 1 over a cand d, the fourth cover being omitted., lhese covers q are of domical form, and give sufficient room for a coil of pipes, a pilot cylinder, or valve and pipe connections, as may be; and provide also for a large body of cooling water surrounding the cylinders and air pressure pipes to insure sulicient water cooling, and promote eiiciency in compressing air.

What I claimand desire to secure by United States Iatentisz- 1. A multiple stage air compressor having 1n combina tion e hollow ring shaped frame' with radial openings at equal distances apart concentrically arranged through lts inner and outer walls; a pair of main cylinders opposltely placed in openings of the inner wall each having a pilot cylinder, and aplston common to said main and pilot cylinders; a connecting rod plvoted to each main piston; a pair of smaller cylinders oppositely placed ln the remaining openings of the inner wall; plunger pistons connected by a yoke adapted to workin said smaller cylinders; a slipper *crossheadt and a revoluble crank shaft and pin, said pin being adapted to work in sald slipper and transmit lts motion through said yoke and connectlng rods to said pistons, substantially as described.

2. A multiple stage air compressor having ln combination a hollow ring shaped frame with radial ppenings at equal distances apart concentrlcally arranged through lts inner and outer walls; a pair of maln'cylinders oppostely placed in openings of the 'inner wall `each having a pilot cylinder, and a piston common to said main and pilot cylinders; a connecting rod plvoted to ,each maln piston; n pair of smaller cyllndersopposltely placed in the remaining openings of the inner wall; plunger pistons connected by a yoke adapted to work in said smaller cylinders; a slipper crosshead; a revolublecrank sha'ft and pin, said pin being .adapted to work in said slipper and transmit its motion through sold yoke and connecting rods to said pistons; and an electric motor having said crank 'shaft arranged as lts armature shaft, substantially as described. Y

3. A multiple stage air compressor having ln combination a hollow ring shaped frame with radial openings at equal distances apart concentrically arranged through its inner and outer walls; a pair of main cylinders opposltely placed in openings of the inner wall each having a pilot cylinder, and a piston common to'sald main and pilot cylinders, s. connecting rod plvoted to each main piston; a pair of smaller cylinders oppositely placed in the remaining openings of the inner wall; plunger pistons con-A nected by a .yokel adapted to work in said smaller cyllnders;' a slipper crosshead; a revoluble crank shaft and pin, said pin belng`adapted to Work in said slipper and transmit. lts motion throughsaid yoke and connecting rods to said pistons; an-electrlc motor adapted to drlve said crank shaft; covers-to said Aopenings in 'said outer wall; lmeans for connecting sold cylinders, and trnnsmittlng air between'the inner and outer walls ofthe ring shaped frame, substantlally as described.

4. A multiple stage alr compressor having in combinatlon .a hollow ring-shaped framewith openings at equal distances apart through its inner and outer walls; a pair ot main cylinders oppositely placed in openings of the inner wall each having n pilot cylinder, and a piston common to said main and pilot cylinders; a space m at crank shaft; means for covering said openings in said the back of each pilot piston communicating with an air outer wall; and means for transmitting air between said pressure space; a connecting rod pivoted to each mainl cylinders, substantially'as described. l

piston; a pair of smaller cylinders oppostely placed In testimony whereof I have signed this specification in 5 in the'remairiing openings of the inner wall; plunger the presence of two subscribing witnesses.

pistons connected by a yoke adapted to work in said A smaller cylinders; a slipper crosshead, a revoluble crank WILLIAM REAVELL' shaft and pin, 'said pin being adapted to work in said Witnesses: slipper and translnit its motion through said yoke and H. D. JAMESON,

'10 connecting rods to said pistons; means for driving said F. L. RAND. 

